FIG. 4 shows a conventional chair (10) which includes a back portion (101) and a seat portion (102) with a plurality of slats (13) fixedly connected between the two side tubes (103, 104) of the back portion (101) and the seat portion (102). Two arms (11) connected between the back portion (101) and the seat portion (102), and two front legs and two rear legs (12) respectively extend from the two arms (11). It is noted that the side tubes (103, 104) are cylindrical tubes so that the side tubes (103, 104) are pressed to have a plurality of flat recesses to conveniently allow the bolts extending therethrough to fixedly attach the slats (13). It takes time to further press the side tubes (103, 104) to form the flat recesses and therefore increases the manufacturing costs. In addition, the positions of the flat recesses have to be checked carefully to ensure that each pair of the flat recesses are located in the same horizontal plane so that the slat fitted into the corresponding pair of the slots is attached horizontal.
The present invention intends to provide a chair structure comprising two flanges extending from each of the side tubes so that the slats are conveniently fitted into the slots defined by the flanges of the two side tubes. The chair structure of the present invention overcomes the shortcomings found in the conventional chairs mentioned above.